El Salvador - GFDRR

V. RISK MANAGEMENT | 119
programs and projects, establishing guidelines for land use and environmental planning, and providing
scientific-technical support for the design, installation and operation of early warning systems.
Finally, it is necessary to reinforce and streamline coordination and communication mechanisms
among D-SNET, the National Commission for Civil Protection and the Bureau of Civil Protection so that
these institutions can be strengthened and can work in synergy on risk management activities. One very
important aspect is to ensure that the Bureau of Civil Protection and Disaster Prevention and Mitigation
has priority, immediate access to D-SNET’s information and technical personnel, eliminating any administrative
barrier that could reduce Civil Protection’s ability to access and integrate critical information in its
decision-making processes in order to warn the population of the possibility of a natural threat.
Structural measures to reduce exposure to lahars, landslides and floods that may be suggested based
on experience and the current situation in the country include:
a)
b)
c)
Establishing physical protection measures in Verapaz, San Vicente and Guadalupe.
Relocating houses located in the most exposed zones to zones of lesser risk.
Improving the drainage systems of roads and highways to avoid erosion and damage to road fill.
More specifically, the following measures, focused on places and types of work, are recommended.
Lahars on the San Vicente (Chinchontepec) Volcano 56
Canalization combined with deflecting walls in the lower part of slopes as the most appropriate measure
for larger lahars. Other measures in the upper parts of slopes do not appear to be feasible. For Verapaz
and Guadalupe, preliminary safety measures are proposed, to be conducted jointly by D-SNET/MOP.
A deflecting wall in Verapaz is proposed, with a height of no less than 10 meters and a length of 850
meters. The material resulting from the excavation of sediment now deposited in the canal could be used
for filling. Preliminary NGI calculations indicate that the approximate cost of this work would be US$3
million, including the construction of a new bridge. It is vitally important to carry out work to clear the
materials deposited in the canal following each rainy season in order to maintain its capacity. The major
challenge is to keep large volumes from accumulating behind the retaining wall, reducing its effective
height.
In Guadalupe the excavation of the riverside canal should be accompanied by the restoration of sufficient
transverse space. In a preliminary manner, it is suggested that the riverbed area be expanded to at
least 100 m 2 . It is necessary to excavate the other river courses that were saturated by lahar materials.
Since nearly all of Verapaz is exposed to new events, a decision should be made to gradually move it
toward a less risky location, approximately 100 meters to the east. This move should take into account social
and environmental considerations in order to minimize its impact. For Tepetitán, a decision was made
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Further studies are needed to establish all intervention costs. Only the US$3 million for immediate construction of a
deflecting wall are taken into account.